The present invention relates to a hydraulic lift system for use in connection with adjustable work surfaces and particularly to a rotatable coupling to facilitate installation.
As the work place environment changes with technology, so too do the facilities employed by companies to provide ergonomically appropriate work stations for technical, clerical, and assembly personnel. To accommodate different job tasks, frequently it is desirable to have a work surface or table which is vertically adjustable, such that the work surface can be employed by individuals of different stature and individuals in a standing position, a sitting position on a chair, or in an intermediate position when using, for example, a stool-height seat.
There exists numerous adjustable table assemblies which are either mechanically controlled by screw jack mechanisms or which are electrically controlled screw jacks. Some installations employ hydraulic cylinders with a pump for pressurizing fluid from a master cylinder to slave cylinders mounted within hydraulic lifts secured to the legs of a table for controlling the vertical adjustment of the work surface. One such system is commercially sold by Suspa Incorporated under the trademark MOVOTEC®, which includes a hydraulic support tube assembly for each table leg. Each support tube assembly including an outer housing, a support tube extendable from the housing and an inner hydraulic cylinder which is coupled between the outer housing and support tube and includes a piston rod which extends and retracts for raising and lowering the support tube for extending and retracting the support tube from the housing. U.S. Pat. No. 6,711,985 discloses an improved sealed glide adapter used with such system. The disclosure of U.S. Pat. No. 6,711,985 is incorporated herein by reference.
The hydraulic cylinder in the '985 patent disclosure is locked against rotation by a connecting head that includes an upper annular offset section which engages the keeper pins holding the cylinder within the support tube. Upon installation of the lift, it is necessary to align the hydraulic supply tube with respect to the table and source of pressurized fluid employed to actuate the lift. Since the hydraulic cylinder is prevented from rotation and the support tube is secured to the table leg, this installation can become difficult and may require the undesirable use of additional coupling elbows or flexible tubing. Also, typically space above a cylinder lift is limited so that mounting a standard hydraulic coupling is difficult.
Thus, there exists a need to overcome these problems and provide a hydraulic cylinder with a sealed glide adapter and which has a compact, low profile connecting head which can be rotated to facilitate installation to an existing table leg.